What is the Difference Between POP and IMAP Email Services?

Do you understand the difference between how POP and IMAP email services function?

IMAP is a standard protocol used to retrieve e-mail messages from a mail server using e-mail client software such as Outlook, however POP is a still used in some cases, mainly because it is easy to implement.

The Internet Message Access Protocol or IMAP has helped to overcome the limited functionality that POP offers, such as having the ability for multiple email clients to manage the same email account. Depending on the IMAP client implementation and configuration, users normally have the ability to save messages directly on a computer / mobile device, or just save email on the server, or both on the client and the server. IMAP also provides the ability for email clients like Outlook to sync emails, contacts, calendars, and other features; all tied into local email clients and/or applications.

Information about IMAP email features and functionality:

By default, local copies of emails are downloaded and email messages will remain on server until they are manually deleted.

Multiple email clients are able to connect to the same mailbox at the same time.

Email clients are able to detect changes made to the mailbox by other clients that are concurrently connected.

Users are able to search the contents of all messages in the account without having to download all email messages in to a local mailbox.

When using IMAP, all folders should be created within the root email account folder and NOT “nested” within the inbox. When folders are created within the inbox, folders may have trouble completing the sync process.

The Post Office Protocol or POP, is a much simpler protocol, making implementation easier. POP email is also referred to as POP3, because version 3 is the latest release of the POP protocol standards.

Today POP is becoming obsolete, replaced by the more advanced IMAP email protocol. In comparison to how IMAP functions, when using POP email is downloaded from the server's inbox to your computer. Think of the POP email protocol like a 1-way pipe, email is only sent from the server to the email application or client. Changes within the account like flagged email message are not sent and do not sync back to the server or to other devices that are connected to the email account.

POP mail moves the message from the email server onto your local computer, although depending on the email client, application, or device used to check email, there is usually an option to leave the messages on the email server as well.

It is important to note that POP has no concept of folders, which means that creating or storing emails in folders, as well as changes to folders in Outlook and other email clients, will not sync to the server or other devices that have access to the same email account. In comparison, IMAP does allow remote mailboxes to be manipulated as if they were local. For example, when using IMAP, emails are able to be flagged/labeled as "deleted" and the emails will still remain on the device or computer and server until the messages are manually deleted or purged. This functionality is not available when using POP.The POP email protocol only allows one active connection to an email client mailbox at a time, which is why it’s never recommended to use both POP and IMAP when setting up email accounts on multiple devices. As an example, say your business email account is setup using IMAP on the computer in your office. If you want to have the ability to check emails while out of the office, it would be important to select the option to setup all new email accounts also using the IMAP option for cell phones, laptops, mobile devices, and/or other computers. Be aware that creating both IMAP and POP accounts on different devices can cause multiple copies of the same emails being generated.

Whether you are creating a new business email account or new personal email account, understanding how IMAP and POP protocols are different can help save time and help to avoid frustrations with how email is handled, especially when accessing the same email on multiple devices. Thinking ahead and setting up email accounts on the protocol that best fits your short and long term plans for your business or personal needs will help to avoid the hassles of migrating from POP to IMAP.